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Home >> Toyota >> 2003 >> Matrix Base, FWD, Automatic >> Repair and Diagnosis >> External Pages >> Different car >> Section 86 (Engine Controls - Self-Diagnostics) >> Diagnostic Tests >> DTC P0442: Evaporative Emission Control System Leak Detected (Small Leak) & DTC P0456: Evaporative Emission Control System Leak Detected (Very Small Leak) >> Diagnosis & Repair (Using OBD-II Scan Tool)
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Diagnosis & Repair (Using OBD-II Scan Tool)

WARNING: This page is about a different car, the 2003 Lexus RX 300. However, it is still accessible from the selected car via links, so may be relevant.
  1. Check that fuel tank cap is LEXUS genuine parts. Replace as necessary. If fuel tank cap is okay, go to next step.
  2. Check that fuel tank cap is correctly installed. Correctly install fuel tank cap. If fuel tank cap is okay, go to next step.
  3. Check fuel tank cap. Replace fuel tank cap as necessary. If fuel tank cap is okay, go to next step.
  4. Check filler neck for damage. Replace filler pipe as necessary. If filler pipe is okay, go to next step.
  5. Check for cracks, deformation and loose connection of fuel tank, charcoal canister, fuel tank filler pipe and hoses and tubes around fuel tank and charcoal canister. See Figure. Repair or replace as necessary. If okay, go to next step.
  6. Check vacuum hoses between vapor pressure sensor and fuel tank, charcoal canister and VSV for pressure switching valve, and VSV for pressure switching valve and charcoal canister. Check that the vacuum hose is connected correctly. Check the vacuum hose for looseness and disconnection. Check the vacuum hose for cracks, holes and damages. Repair or replace as necessary. If okay, go to next step.
  7. Check hose and tube between fuel tank and charcoal canister. Check for proper connection of the fuel tank and fuel evaporation pipe, fuel evaporation pipe and fuel tube under the floor, fuel tube under the floor and charcoal canister. Check the hose and tube for cracks, holes and damages. Repair or replace as necessary. If okay, go to next step.
  8. Check VSV connector for EVAP, VSV connector for CCV, VSV connector for pressure switching valve and vapor pressure sensor connector for looseness and disconnection. Repair or connect VSV or sensor connector. If okay, go to next step.
  9. Check vacuum hoses. Check that the vacuum hose is connected correctly. Check the vacuum hose for looseness and disconnection. Check the vacuum hose for cracks, damage, and blockages. Repair or replace as necessary. If okay, go to next step.
  10. Check voltage between terminals VC and E2 of ECM connector. Remove the glove compartment. Turn the ignition switch ON. Measure voltage between terminals VC and E2 of the ECM connector. See Figure. If 4.5-5.5 volts are present, go to next step. If not, check and replace ECM.
  11. Remove the glove compartment. Turn the ignition switch ON. Measure the voltage between terminals PTNK and E2 of the ECM connectors. Disconnect the vacuum hose from the vapor pressure sensor. Using the MITYVAC (Hand-Held Vacuum Pump), apply a vacuum of 1.18 in. Hg (4.0 kPa, 30 mm Hg) to the vapor pressure sensor. Vacuum applied to the vapor pressure sensor must be less than 19.7 in. Hg (66.7 kPa, 500 mm Hg). See Figure. If voltage is 2.9-3.7 volts, or 0.5 volts or less, go to step  13. If voltage is not to specification, go to next step.
  12. Check for open and short in harness and connector between vapor pressure sensor and ECM. Repair or replace harness or connector as necessary. If harness is okay, replace vapor pressure sensor.
  13. Remove the glove compartment. Turn the ignition switch ON. Check the VSV function. Connect jumper wire between terminal EVP1 of the ECM connector and body ground, then disconnect wire. When VSV is ON, air flows from port "E" out through port "F". When VSV is OFF, air does not flow from port "E" to port "F". See Figure. If okay, go to step  16. If not okay, go to next step.
  14. Check operation of VSV for EVAP. See FUEL EVAPORATION SYSTEM in SYSTEM & COMPONENT TESTING - ES300 & RX300 article. If okay, go to next step. If not okay, replace VSV and clean vacuum hoses between throttle body and VSV for EVAP, and VSV for EVAP and charcoal canister, and then check charcoal canister.
  15. Check for open and short in harness and connector between EFI relay and VSV for EVAP, and VSV for EVAP and ECM. Repair or replace harness or connector. If okay, check and replace ECM.
  16. Remove the glove compartment. Turn the ignition switch ON. Check the VSV function. Connect jumper wire between terminal CCV of the ECM connector and body ground, then disconnect wire. When VSV is ON, air does not flow from port "E" to port "F". When VSV is OFF, air from port "E" flows out through port "F". See Figure. If okay, go to step  19. If not okay, go to next step.
  17. Check operation of VSV for CCV. See FUEL EVAPORATION SYSTEM in SYSTEM & COMPONENT TESTING - ES300 & RX300 article. If not okay, replace VSV and charcoal canister, and then clean vacuum hose between charcoal canister and VSV for CCV. If okay, go to next step.
  18. Check for open and short in harness and connector between EFI relay and VSV for CCV, and VSV for CCV and ECM. Repair or replace harness or connector as necessary. If okay, check and replace ECM.
  19. Remove the glove compartment. Turn the ignition switch ON. Check the VSV function by connecting jumper wire between terminal TBP of the ECM connector and body ground, then disconnect wire. When VSV is ON, air from port "E" flows out through port "F". When VSV is OFF, air does not flow from port "E" to port "F". See Figure. If okay, go to step  22. If not okay, go to next step.
  20. Check operation of VSV for pressure switching valve. See FUEL EVAPORATION SYSTEM in SYSTEM & COMPONENT TESTING - ES300 & RX300 article. If okay, go to next step. If not okay, replace VSV and charcoal canister, and then clean vacuum hoses between charcoal canister and VSV for pressure switching valve, and VSV for pressure switching valve and fuel tank.
  21. Check for open and short in harness and connector between EFI relay and VSV for pressure switching valve, and VSV for pressure switching valve and ECM. Repair or replace harness or connector. If okay, check and replace ECM.
  22. Check the fuel tank over fill check valve. Replace fuel tank over fill check valve or fuel tank as necessary. If okay, check and replace charcoal canister.
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